uhmm, I think your directing that at the wrong people lol. this is XBMCHUB.com where you get the best addons. I think you want to let the guys over at XBMC.org know about it. with that said, when a video is playing use your mouse or arrow keys to navigate over to the speaker icon. if you select it you can adjust the audio offset and then when done, hit back to get back to the audio menu. then at the bottom, hit "set as defualt for all videos". that should help get things back in sync
I backed mine down 0.225 sec and it took care of it.
like said though, XBMC.org wrote the code for the player (its part of xbmc itself) so It might help to talk to them about it. I only know about adjusting the offset to fix it